As with school age children, it is difficult to make conclusions about the validity of available dietary assessment instruments for adolescents because of the differences in instruments, research designs, reference methods, and populations in the validation literature. Many of the research needs identified for adolescents are similar to those identified for school age children:

Examination of the validity and reliability of each dietary assessment method by age, gender, ethnic subgroup, and socioeconomic status is necessary to understand the best application of each tool (1).

Development and validation of improved methods for assessing dietary supplement use is needed (9;64).

Physiologically-based measures, such as doubly labeled water or serum micronutrient concentrations merit further study because these reference measures are not affected by respondent error; (1;161;201) a more extensive database of assessments of TEE (Total Energy Expenditure) by the DLW (Doubly Labeled Water) method is needed.

Identification and characterization of subgroups most likely to misreport food intakes, together with the reasons for doing so, needs further study, along with the development of improved techniques to identify underreporters and overreporters at the individual level (161;201).

The issue of whether underreporting of diet applies to the diet as a whole or whether there is selective underreporting of nutrient intake, whether by food types, meals or snack foods needs examination (161).

The reasons for, effects of, non-participation by children and adolescents should be examined to identify possible sources of bias (non-response bias) and to assess implications for design analysis, and interpretation of results (161;217).

The effect of body size on reporting of dietary intake requires further study (1;161).

The effects of a longer time lag between meal recall and environmental factors on the accuracy of recall in adolescents need to be established (202).

More research is needed on the prompts that can aid memory retrieval at various ages without increasing the risk of eliciting socially-desirable responses. Environmentally specific probes (e.g., school, fast food restaurants, extracurricular activities, media and entertainment, food industry packaging of foods for children) within a food record or food frequency questionnaire also are needed (160;161;206;218).

Refinement of statistical techniques to account for systematic bias in pediatric populations is needed. Statistical models need to be developed that will estimate the impact of systematic bias on estimates such as relative risk, variance ratios, or proportions on the populations with inadequate intakes (161).